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Abstract:

An endoscopic imaging system for examining a patient's body cavity
includes an endoscope having a distal end, a proximal end and a number of
lumens therein. One or more distal gas ports are disposed at or adjacent
the distal end of the endoscope and one or more proximal gas ports are
disposed proximal to the distal gas ports. Insufflation gas is delivered
to the distal gas ports and withdrawn from the proximal gas ports or vice
versa such that a gas bubble is formed in the body cavity and travels
with the distal tip of the endoscope.

Claims:

1-6. (canceled)

7. A system for automatically controlling the delivery of insufflation
gas, the system comprising: a control cabinet including a processor; one
or more valves configured to control the delivery of insufflation gas to
a patient; and a tube removably connected to the control cabinet and
including one or more sensors at a distal end of the tube; wherein the
processor is configured to obtain sensor readings from the one or more
sensors and automatically control insufflation gas delivered to the
patient as a function of the sensor readings.

8. The system of claim 7, wherein the one or more sensors includes an
image sensor.

9. The system of claim 8, wherein the delivery of insufflation gas is
controlled to maintain a predefined field of view in the image signals
produced by the image sensor.

10. The system of claim 7, wherein the one or more sensors includes a
sensor configured to determine a pressure in a body cavity, wherein the
processor is configured to control the delivery of insufflation gas to
maintain a predetermined pressure in a body cavity.

11. The system of claim 7, wherein the tube is dispensable.

12. A system for automatically controlling the delivery of insufflation
gas, the system comprising: a control cabinet including a processor; at
least one valve configured to control the delivery of insufflation gas;
and a tube removably connected to the control cabinet and including at
least one sensor at a distal end of the tube; wherein the processor is
configured to receive sensor readings from the at least one sensor and
automatically control the delivery of insufflation gas as a function of
the sensor readings by controlling actuation of the at least one valve.

13. The system of claim 12, wherein the at least one sensor includes an
image sensor.

14. The system of claim 13, wherein the processor is configured to
control the delivery of insufflation gas to maintain a predefined view
produced by the image sensor.

15. The system of claim 12, wherein the at least one sensor includes a
sensor configured to determine a pressure in a body cavity and an image
sensor configured to produce image signals in the body cavity, and
wherein the processor is configured to control the delivery of
insufflation gas to maintain a predetermined pressure in the body cavity
and to maintain a predefined view produced by the image sensor.

16. The system of claim 12, further comprising a manifold configured to
supply insufflation gas, a liquid, and aspiration to the tube.

17. The system of claim 16, wherein the at least one valve is configured
to control the supply of insufflation gas, the liquid, and aspiration
from the manifold.

18. The system of claim 17, wherein the tube is removably coupled to the
manifold.

19. A system for automatically controlling the delivery of insufflation
gas, the system comprising: a control cabinet including a processor; at
least one valve configured to control the delivery of insufflation gas;
and a tube removably connected to the control cabinet and including at
least one sensor configured to determine a pressure in a body cavity;
wherein the processor is configured to receive pressure sensor readings
from the at least one sensor and automatically control the delivery of
insufflation gas to maintain a predetermined pressure in the body cavity
by controlling actuation of the at least one valve.

20. The system of claim 19, further comprising an image sensor.

21. The system of claim 20, wherein the processor is configured to
control the delivery of insufflation gas to maintain the predetermined
pressure in the body cavity and to maintain a predefined view produced by
the image sensor.

22. The system of claim 19, further comprising a manifold configured to
supply insufflation gas, a liquid, and aspiration to the tube.

23. The system of claim 22, wherein the at least one valve is configured
to control the supply of insufflation gas, the liquid, and aspiration
from the manifold.

24. The system of claim 23, wherein the tube is removably coupled to the
manifold.

Description:

FIELD OF THE INVENTION

[0001] The present invention relates to an automatic medical insufflation
device for diagnostic and surgical endoscopy. In particular, it relates
to a system for and method of creating and controlling an observation
space within a human body cavity so as to optimize diagnostic and/or
surgical endoscopy by insufflation.

BACKGROUND OF THE INVENTION

[0002] Endoscopes have been used in the medical field for many years to
look within a selected region of a patient's body, e.g., the colon. The
endoscope is typically inserted through an orifice or a surgical incision
into a body channel or cavity. Endoscopes are commonly used to perform
surgical, therapeutic, diagnostic, or other medical procedures under
direct visualization. Conventional endoscopes generally contain several
endoscope components, including illuminating means such as light-emitting
diodes or fiber optic light guides connected to a proximal source of
light, imaging means such as a miniature video camera or a fiber optic
image guide, and a working channel. Flexible endoscopes incorporate an
elongated flexible shaft and an articulating distal tip to facilitate
navigation through the internal curvature of a body cavity or channel.
Examples of conventional endoscope designs are described in U.S. Pat. No.
4,706,656, No. 4,911,148, and No. 5,704,899.

[0003] Typical endoscopes provide a conduit for the delivery of an inert
gas to insufflate the colon to facilitate examination. The colon, which
collapses upon itself when empty, must be inflated to create a space,
thereby creating a clear field of view for visualization. In order to
insufflate the colon, conventional endoscopic systems utilize an air
compressor or other similar gas supply sources. Insufflation creates a
space for visualization and keeps the gas pressure constant within the
colon by controlling the pressure of the gas supply by means of valves,
pressure regulators, and other control devices.

[0004] In a standard endoscopic procedure, an operator actively monitors
and manually maintains set-point pressure and flow values by checking the
displays and operating the controls of the insufflation device. Because
many systems do not provide quantitatively accurate methods of regulating
the delivery of the gas, those systems can allow variations in the
pressure, volume, and flow rate of gas administered during an endoscopic
procedure.

[0005] In addition, air pressure in the colon is a cause of pain for the
patient, both during the procedure and afterwards, due to distension of
the bowel if the pressure is not abated. Furthermore, excess insufflation
pressure can potentially stress, or even rupture, the colon during the
colonoscopy or may cause the development of late perforations if the
pressure and volume of the insufflating gas is not accurately controlled
and promptly released.

SUMMARY OF THE INVENTION

[0006] To address the problems associated with conventional endoscopic
insufflation systems, the present invention decreases patient discomfort
due to insufflation of a body lumen and allows a physician a clear field
of view of an interior body cavity. The present invention automatically
controls insufflation and exsufflation parameters based on different
operating modes of the system and/or based on body cavity characteristics
viewed by the endoscope. In one embodiment, the present invention is an
endoscopic imaging system of the type that includes an elongated shaft
having a proximal end and a distal end. The shaft includes one or more
distal gas ports at or adjacent the distal end of the shaft and one or
more proximal gas ports. The endoscope is removably connected to a
control unit having an insufflation gas supply and a gas venting system.
Insufflation gas is selectively delivered to the distal gas ports and
withdrawn from the proximal gas ports or vice versa during an endoscopic
examination so that a gas bubble is formed around the distal end of the
endoscope. The gas bubble travels with the distal tip as the endoscope is
inserted into or withdrawn from the lumen.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The foregoing aspects and many of the attendant advantages of this
invention will become more readily appreciated as the same become better
understood by reference to the following detailed description, when taken
in conjunction with the accompanying drawings, wherein:

[0008] FIG. 1 illustrates a single-use endoscopic imaging system in
accordance with one embodiment of the present invention;

[0009] FIG. 2 is a functional block diagram that shows the
interrelationship of the major components of a single-use endoscopic
imaging system shown in FIG. 1;

[0010] FIG. 3 illustrates a distal end of a single-use imaging endoscope
in accordance with an embodiment of the present invention;

[0011] FIGS. 4A and 4B illustrate an imaging sensor and heat exchanger
positioned at the distal end of the endoscope in accordance with an
embodiment of the present invention;

[0012] FIG. 5 illustrates a gas bubble created by the present invention
that moves with the distal tip of an endoscope; and

[0013] FIG. 6 is a flow diagram of an exemplary method of insufflation and
exsufflation using the single-use imaging endoscope in accordance with
the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0014] As indicated above, the present invention is an endoscopic imaging
system that performs automated insufflation for use with diagnostic and
surgical endoscopy. Although the present invention is described with
respect to its use within the colon, it will be appreciated that the
invention can be used in any body cavity that can be expanded for
examination and/or surgery.

[0015] FIG. 1 illustrates the major components of an exemplary single-use
endoscopic imaging system 10. The components of the system 10 include a
display 12, a user input device 16, and a single-use imaging endoscope
18, all of which are functionally connected to a control cabinet 14 that
executes application software (not shown) residing therein. Display 12 is
any special-purpose or conventional computer display device, such as a
computer monitor, that outputs graphical images and/or text to a user.
Single-use imaging endoscope 18 is a single-use flexible tube that
contains one or more lumens for the purpose of performing endoscopic
procedures and facilitating the insertion and extraction of fluids,
gases, and/or medical devices into and out of the body. Single-use
endoscope 18 further contains a digital imaging system (not shown)
comprised of, in one example, an image sensor such as a CMOS imager,
optical lenses such as plastic optics, a light source such as a number of
LEDs, and an articulating tip that enables steering of the endoscope in a
desired direction.

[0016] Control cabinet 14 is a special-purpose electronic and
electro-mechanical apparatus that processes and manages all system
functions, and includes a network-enabled image-processing CPU, a
physical connection to the single-use endoscope 18, an optional dock for
the user interface 16, and valves that control the delivery of gas/water
to the endoscope and a vacuum line that removes the air/gas and debris,
etc., from the patient. User input device 16 is a hand-held device,
either wired to the control cabinet 14 or wireless, that accepts inputs
from a human operator via standard push buttons, joysticks, or other
activation devices either singularly or in combination to control the
operation of single-use endoscopic imaging system 10.

[0017] Operation of single-use endoscopic imaging system 10 is as follows:
the system is initiated and operated upon command by means of user input
device 16, causing the application software executed by a processor
within the control cabinet 14 to activate the appropriate hardware to
perform surgical, therapeutic, diagnostic, or other medical procedures
and to deliver insufflation and/or suction to the lumen(s) of single-use
endoscope 18. Display 12 provides live endoscopic video images and visual
feedback of control parameters to the physician or operator so that an
examination of the patient can be completed. Upon termination of the
examination, the endoscope 18 is disconnected from the control cabinet
and disposed of.

[0018] FIG. 2 is a functional block diagram of single-use endoscopic
imaging system 10 that shows the operational interrelationship of the
major hardware and software elements of the system. A complete
description of the control cabinet 14 and other components is set forth
in U.S. patent application Ser. No. 10/811,781, filed Mar. 29, 2004, and
is herein incorporated by reference. The single-use endoscopic imaging
system 10 includes the control cabinet 14 that operates to control the
orientation and functions of a single-use imaging endoscope 18. The
control cabinet 14 includes a controller interface 106 that receives
commands from the user input device such as a joystick, that is used by a
physician or their assistant to control the operation of the single-use
imaging endoscope. Commands from the joystick are supplied to a
programmable processor such as a digital signal processor that controls
the overall operation of the imaging system and a servo control unit 108.
The processor and servo control unit 108 control the operation of a pair
of servo motors 110, 112 that in turn drive control cables within the
single-use endoscope 18. The orientation of the distal tip is controlled
in response to directional signals received from the user input device as
well as feedback signals obtained from sensors that measure the position
and torque of each of the servo motors 110, 112.

[0019] In one embodiment of the invention, the processor and servo control
unit 108 implement a position-to-rate control that varies the speed at
which the distal tip is moved as a function of the position of the
directional switch on the user input device. However, other control
algorithms such as position-to-position or position-to-force (i.e.,
acceleration) could also be implemented.

[0020] The control cabinet 14 also includes an imaging board 114 that
produces images from the signals that are received from the image sensor
at the distal end of the single-use endoscope 18. The imaging board 114
deserializes the digital video signal from the CMOS imager and performs
the necessary algorithms such as demosaicing, gain control and white
balance to produce a quality color image. The gain control of the system
is implemented by adjusting the intensity of the illumination (current
supplied to a number of LEDs) and adjusting the RGB gains to the CMOS
imager. The imaging board 114 also includes isolation circuitry to
prevent a patient from becoming shocked in the event of an electrical
failure on the imaging board 114 or within the control cabinet 14 as well
as circuitry for transmitting control signals to the image sensor and for
receiving image signals from the image sensor. In one embodiment of the
invention, the imaging board 114 is provided on a standard PC circuit
board to allow individual endoscopes to be tested with a personal
computer and without the need for an additional control cabinet 14.

[0021] In the embodiment shown in FIG. 2, the single-use endoscope 18 has
a distal shaft portion 120 that is connected to a breakout box 122 with a
swivel connection 124. In addition, the proximal portion 126 of the shaft
is connected to the breakout box 122 with a second swivel connection 128.
The swivel connections 124, 128 allow the distal and proximal ends of the
endoscope to rotate with respect to the breakout box 122 and without
twisting the breakout box 122 in the hands of the physician or their
assistant.

[0022] In the embodiment shown, the single-use endoscope 18 is connected
to the control cabinet 14 with a connector 130. Within the connector 130
are a pair of spools 132, 134 that are engageable with the driveshafts of
the servo motors 110, 112. Each spool 132, 134 drives a pair of control
cables in opposite directions. One pair of control cables drives the
distal tip of the endoscope in the up and down direction, while the other
pair of control cables drives the distal tip of the endoscope in the left
and right direction.

[0023] The connector 130 also includes a manifold 140 that controls the
supply of fluid, air and vacuum to various tubes or lumens within the
endoscope 18. In addition, the connector 130 includes an electrical
connector 142 that mates with the corresponding electrical connector on
the control cabinet 102. The connector 142 transfers signals to and from
the image sensor as well as power to the illumination LEDs and allows
connection to a thermal sensor at the distal end of the endoscope. In
addition, the connector 142 carries signals from a remote pressure sensor
as will be described below. Water or another liquid is supplied to the
endoscope with a pump 145. The pump 145 is preferably a peristaltic pump
that moves the water though a flexible tube that extends into the
proximal connector 130. Peristaltic pumps are preferred because the pump
components do not need to come into contact with the water or other
fluids within the endoscope and it allows the wetted component to be
single-use. A water reservoir 150 connected to the pump 145 supplies
water to cool the illumination LEDs as well as to irrigate the patient.
The water supplied to cool the LEDs is returned to the reservoir 150 in a
closed loop. Waste water or other debris are removed from the patient
with a vacuum line that empties into a collection bottle 160. Control of
the vacuum to the collection bottle 160 is provided at the manifold 140
within the proximal connector 130. A gas source provides insufflation by
delivering an inert gas such as carbon dioxide, nitrogen, air, etc., to
the lumen(s) of single-use endoscope 18 via the manifold 140.

[0024] The processor and control unit 108 executes application software,
including GUI software application, system control software application,
and a network software application that reside on a computer readable
medium such as a hard disc drive, CD-ROM, DVD, etc., or in a solid state
memory. GUI software application is well known to those skilled in the
art, and provides the physician or operator with live endoscopic video or
still images and, optionally, with visual, audible, or haptic control and
feedback on display 12 using user input device 16. System control
software application is the central control program of application
software that receives input from sensors, such as from a pressure sensor
as described below, and from the user input device 16. System control
software application provides system control for the functions necessary
to operate single-use endoscope system 10. The network software
application operates a network connection to allow the endoscopic imaging
system 10 to be connected to a local area network and/or the Internet.

[0025] As set forth in the Ser. No. 10/811,781 application, the manifold
140 supplies insufflation gas, water and vacuum to one or more lumens of
single-use endoscope 18. The manifold is preferably constructed as a
series of passages that are formed between sheets of a thermoplastic
material. Water, air, and vacuum are applied to inputs of the manifold
and selectively delivered to outputs that are in turn connected to lumens
within the endoscope 18 by pinch valves on the control cabinet 14 that
open or close the passages in the manifold. The passages are preferably
formed by rf welding the sheets of thermoplastic into the desired pattern
of the passages.

[0026] In accordance with FIG. 2, the basic process of insufflation and
exsufflation using single-use endoscopic imaging system 10 is as follows:

[0027] During operation, live endoscopic video images are provided on
display 12 by the GUI software application, which processes information
from the imaging board 114, and the single-use endoscope 18. Prior to
operation, insufflation is initiated upon operator command by means of
the user input device 16. As a result, system control software
application activates the manifold 140 by means of the pinch valves on
the control cabinet 14. Upon advancing single-use endoscope 18, an
insufflation gas is channeled through a dedicated lumen 175 of single-use
endoscope 18 and into the patient. In one embodiment of the invention, as
shown in FIG. 3, the gas delivery lumen terminates at directional port
256, that directs the insufflation gas and/or water over a lens 270 of
the imaging sensor. As the distal tip of single-use endoscope 18 is
advanced into the colon during the endoscopic procedure, further areas of
the colon are insufflated, bringing new examination regions into view.

[0028] As single-use endoscope 18 is advanced through the colon, the
region of the previous field of view is simultaneously exsufflated
(collapsed), by connecting the vacuum source to one or more proximal gas
ports 190 that exit on the exterior of the endoscope shaft and are
positioned proximal to the distal gas port(s). The proximal gas ports 190
are connected through a dedicated lumen, or through the "free space"
within the shaft of single-use endoscope to the proximal end of the
endoscope. To collapse the gas bubble, the manifold 140 is activated by a
pinch valve to apply vacuum through the one or more proximally located
gas ports 190. By this means, the body cavity is deflated directly behind
the tip of single-use endoscope 18, thus forming a traveling insufflation
bubble within the body cavity.

[0029] As shown in FIG. 4A, the distal end of the single-use endoscope 18
includes a distal cap 250 having a number of openings on its front face.
The openings include an opening to a working channel 252 and an opening
254 for a low pressure lavage, whereby a stream of liquid can be
delivered through the endoscope for removing debris or obstructions from
the patient. A lens wash and insufflation port includes an integrated
flush cap 256 that directs water across the lens of an image sensor and
delivers the insufflation gas to expand the lumen in which the endoscope
is inserted. Offset from the longitudinal axis of the endoscope is a lens
port 258 that is surrounded by a pair of windows or lenses 260 and 262
that cover the illumination sources. An optional pressure sensor 245 is
also disposed on or adjacent the front face of the distal cap 250 to
detect pressure within the body cavity of the patient. Signals from the
pressure sensor 245 are transmitted back to the processor and servo
control unit 108 through the electrical connector 142. A suitable
pressure sensor 245 is a miniature pressure gauge available from National
Semiconductor Corporation or Konigsberg Instruments, Inc.

[0030] As best shown in FIG. 4A, the imaging assembly also includes a heat
exchanger 280. The heat exchanger 280 comprises a semi-circular section
having a concave recess 282 into which a cylindrical lens assembly 270 is
fitted. The concave recess 282 holds the position of the lens assembly
270 in directions perpendicular to the longitudinal axis of endoscope,
thereby only permitting the lens assembly 270 to move along the
longitudinal axis of the endoscope. Once the lens assembly is positioned
such that it is focused on an image sensor 290 that is secured to a rear
surface of the heat exchanger 280, the lens assembly is fixed in the heat
exchanger with an adhesive. A pair of LEDs 284, 286 are bonded to a
circuit board that is affixed in the heat exchanger such that a channel
is formed behind the circuit board for the passage of a fluid or gas to
cool the LEDs. A circuit board or flex circuit 292 containing circuitry
to transmit and receive signals to and from the control cabinet is
secured behind the image sensor 290 and to the rear surface of the heat
exchanger 280. With the lens assembly 270, the LEDs 284, 286, the image
sensor 290, and associated circuitry 292 secured in the heat exchanger
280, the heat exchanger assembly can be fitted within the distal cap 250
to complete the imaging assembly.

[0031] FIG. 5 illustrates a single-use endoscope 18 that is inserted into
a body cavity such as a colon. As the single-use imaging endoscope 18 is
advanced, gas is delivered through the one (or more) distal gas
insufflation ports to inflate a bubble 502 surrounding the distal end of
the single-use imaging endoscope 18. Gas is withdrawn from the proximal
gas exsufflation ports 190 to collapse the colon at an area 504 proximal
to the distal end of the endoscope 18. As the endoscope 18 is moved
distally, the bubble moves distally, as indicated by bubble 506 as shown
in phantom lines.

[0032] When retracting the endoscope during the examination, the operator
enters the appropriate command on user interface 116, whereby the system
electronics cause the manifold 140 to reverse the functions of the
proximal and distal gas ports at the tip of single-use endoscope 18. That
is, insufflation gas is supplied to the proximal gas ports 190 and vacuum
is applied to the distal insufflation ports or another port such as the
entrance to the working channel (not shown) located at or adjacent the
distal tip of single-use endoscope 18.

[0033] As indicated above, the distal end of the single-use endoscope 18
includes an optional pressure sensor 245 that allows the processor and
servo control 108 in the control cabinet 14 to regulate the pressure of
the insufflation to provide a clear field of view while reducing patient
discomfort and lessening the likelihood of potential injury.

[0034] FIG. 6 is a flow diagram of a method 400 for the process of
insufflation and exsufflation using a single-use imaging endoscope 18 in
the single-use endoscopic imaging system 10 of the present invention.
FIGS. 1 through 3 are referenced throughout the steps of method 400.
Method 400 includes the following steps:

[0038] In this step, the operator selects an endoscopic operating mode via
user interface 16 based on whether the operator is advancing or
retracting single-use endoscope 18 within the colon. During operation, if
the operator does not change the operating mode, the system maintains its
current operating mode. Method 400 proceeds to step 414.

[0039] Step 414: Advancing or Retracting Endoscope

[0040] In this step, system control software activates manifold 140,
through the control of systems electronics. If the operator chose the
advancing mode in step 412, manifold 140 connects an insufflation gas
source to the distal gas port and connects a vacuum line to proximal gas
ports 190 adjacent the distal end of single-use endoscope 18 or vents the
proximal gas ports to the atmosphere. If the operator chose the
retracting mode in step 412, manifold 140 connects insufflation gas
source to the proximal gas ports 190 and connects the vacuum line to the
distal gas port at the distal end of single-use endoscope 18 or vents the
distal gas port to the atmosphere. Method 400 proceeds to step 416.

[0041] Step 416: Reading Pressure

[0042] In this step, system electronics samples the output of pressure
sensor 245. Pressure sensor 245 measures the insufflation pressure in the
colon. The resultant pressure data is passed to the system control
software. Method 400 proceeds to step 418.

[0043] Step 418: Pressure Greater than Upper Limit?

[0044] In this decision step, system control software compares the
insufflation pressure read in step 416 with a predefined maximum limit in
the range of 0.1 to 0.5 atmospheres 2-4 psig and determines whether the
pressure read in step 416 exceeds this limit. If yes, method 400 proceeds
to step 420; if no, method 400 proceeds to step 422.

[0045] Step 420: Reducing Pressure

[0046] In this step, system control software commands manifold 140, to
stop or reduce the flow of insufflation inert gas to distal end 300 of
single-use endoscope 18. Method 400 returns to step 416.

[0047] Step 422: Pressure Less than Lower Limit?

[0048] In this decision step, system control software application 222
compares the insufflation pressure read in step 416 with a predefined
minimum limit in the range of 2-4 psig, and determines whether the
pressure read in step 416 is below this limit. If yes, method 400
proceeds to step 424; if no, method 400 proceeds to step 426.

[0049] Step 424: Increasing Pressure

[0050] In this step, system control software activates manifold 140, to
begin or increase the flow of insufflation inert gas to the distal end of
single-use endoscope 18. Method 400 returns to step 416.

[0054] In this step, system control software commands manifold 140 to
close the inert gas source and vacuum line from the distal end of the
single-use endoscope 18. Method 400 ends.

[0055] While the preferred embodiment of the invention has been
illustrated and described, it will be appreciated that various changes
can be made therein without departing from the scope of the invention.
For example, control of the insufflation gas delivered to the patient may
be based on other sensed signals besides the pressure detected. Maximum
gas pressure and/or flow rate of the gas can be selected by the physician
by viewing images on the display screen or by taking into consideration
depth of insertion of the endoscope, rate of change in gas pressure, age,
sex, size of the patient, etc. It is therefore intended that the scope of
the invention be determined from the following claims and equivalents
thereto.

Patent applications by Anh Nguyen, Woburn, MA US

Patent applications by Dennis R. Boulais, Danielson, CT US

Patent applications by Lucien Alfred Couvillon, Jr., Concord, MA US

Patent applications by Michael S. Banik, Bolton, MA US

Patent applications by BOSTON SCIENTIFIC SCIMED, INC.

Patent applications in class With control or monitoring of endoscope functions

Patent applications in all subclasses With control or monitoring of endoscope functions